JPH10126390A - Synthesis diversity receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the synthesis diversity receiver, in which part of a radio section of the receiver is configured by one system, so as to make the receiver small in size and to reduce the cost while a plurality of branches are provided. SOLUTION: Antennas 31, 32 are alternately switched at a clock frequency whose frequency is twice a sampling frequency of I, Q signals of a baseband part, a reception signal of each branch arranged in time series is demodulated into a baseband signal by an RF amplifier 34, an RF-BPF 35, a mixer 36, an IF-BPF 37, an AGC amplifier 38, an orthogonal detector 39 and LPFs 40, 41, the baseband signal is converted into a digital signal by A/D converters 42, 43 whose sampling frequency is 2fs, the digital signal is given to demultiplexers 44, 45, in which the signal is demultiplexed into I, Q signals of branches 1, 2, detected by a detection section 46, and the signal after the detection is used and diversity synthesis is conducted by a diversity synthesis section 47 and the result is outputted to a demodulation data output terminal 49.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combined diversity receiver for use in mobile communications and the like, and more particularly to a system in which a part of a radio section is constituted by one system to reduce the circuit scale and the size of the apparatus. And a combined diversity receiver.

[0002]

2. Description of the Related Art FIG. 8 shows a configuration of a conventional combining diversity receiver in the case of two branches. In FIG. 8, the combining diversity receiving apparatus includes a radio unit 1 of a first branch 1, a radio unit 2 of a second branch 2, and a baseband unit 3, and a radio unit 1 of the branch 1 has an antenna 4, RF amplifier 5, RF-BPF 6, mixer 7, IF-B
The radio unit 2 of the branch 2 includes an antenna 15, an RF amplifier 16, an RF-BPF 17, a mixer 18, an IF-BPF 19, and an AGC
The baseband unit 3 includes an amplifier 20 and a quadrature detector 21, and further includes LPFs 11, 12, 22, and 23, and an A / D
It comprises converters 13, 14, 24, 25, a detector 26, and a diversity combiner 27. Reference numeral 28 denotes a demodulated data output terminal.

[0003] The combining diversity receiving apparatus constructed as described above operates as follows. The received signal input to the antenna 4 of the branch 1 includes an RF amplifier 5, an RF-BPF 6, a mixer 7, an IF-BPF 8, an AGC amplifier 9, a quadrature detector 10, an LPF 1
After being demodulated into baseband signals by 1 and 12, the signals are detected by a detector 26 through A / D converters 13 and 14.

On the other hand, similarly, the received signal input to the antenna 15 of the branch 2 is the RF amplifier 16, the RF-BPF 17, the mixer 18, the IF-BPF 19, the AGC amplifier 20, the quadrature detector 21, the LPF 22,
A / D converter 2 after demodulated to baseband signal by 23
The signal is detected by the detector 26 through 4 and 25. Diversity combining section 27 performs diversity combining using the demodulated signal of each branch detected by detecting section 26 and outputs the result to demodulated data output terminal 28.

[0005]

However, the above-mentioned conventional combining diversity receiving apparatus requires a plurality of (two in the above example) separate radio units, and has a problem that the apparatus becomes large. Was.

The present invention solves the above-mentioned conventional problems, and provides a combined diversity receiving apparatus in which a part of a radio section is constituted by one system, the circuit scale is reduced, and the apparatus is downsized. The purpose is to do.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a system in which a part of a radio unit of a receiving apparatus is constituted by one system, and a radio unit separately constituted for each branch is connected to a baseband unit. The same as the sampling frequency of the I and Q signals or n
Switch at twice the clock frequency, demodulate the received signal of each branch obtained in time series into a baseband signal,
In the baseband section, each branch is separated, and after detection,
Diversity synthesis is performed.

By doing so, the scale of the receiving circuit can be reduced, and the device can be downsized.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is a combined diversity receiving apparatus having n branches, wherein the combined diversity receiving apparatus is a radio unit separately formed for each branch. A shared receiving unit, a changeover switch for switching the non-shared receiving unit at a clock frequency equal to or n times as high as the sampling frequency of the baseband I and Q signals, and a shared receiving unit sharing a circuit between the branches; A receiving unit comprising a radio unit and a baseband unit for demodulating a received signal into a baseband signal; and a signal separation processing unit for separating the baseband unit from the reception signals of the respective branches arranged in time series for each branch. And a detector for performing baseband detection, and a diversity combiner for diversity combining the demodulated signals of the separated branches. Is obtained by the combining diversity receiving apparatus and has a function of scale of the receiving circuit is miniaturized, it is possible to downsize the apparatus.

[0010] The invention described in claim 2 of the present invention provides:
When the number of branches n is 2, the non-shared receiving unit is configured only with an antenna, the other wireless units are configured as a shared receiving unit, and the changeover switch switches I, I of the baseband unit.
A / D converter that alternately switches at a clock frequency twice as high as the sampling frequency of the Q signal, and samples the demodulated signal at twice the sampling frequency of the I and Q signals in the signal separation processing unit of the baseband unit. And a demultiplexer, which has the function of greatly reducing the size of the receiving circuit and enabling the size of the device to be reduced.

Further, the invention according to claim 3 of the present invention provides:
3. The combined diversity receiving device according to claim 2, wherein the non-shared receiving unit is configured by an antenna and an RF amplifier. The size of a receiving circuit can be reduced, and the device can be downsized. In addition, it has the effect of reducing the interference between the two branches and obtaining a higher diversity effect.

[0012] The invention described in claim 4 of the present invention provides:
The switch is alternately switched at a clock frequency that is twice the sampling frequency of the I and Q signals of the baseband unit, and the signal separation processing unit of the baseband unit is
4. An A / D converter for sampling a demodulated signal at the same frequency as the sampling frequency of the I and Q signals at a timing synchronized with a received signal of each branch. The present invention provides a combined diversity receiver as described in (1) or (2), wherein the scale of the receiving circuit is reduced, the device can be reduced in size, and I and Q signals of the same sampling frequency can be obtained in the baseband section. Since the sampling frequency of the A / D converter is only half that of the combined diversity receiver according to the second aspect, it is possible to reduce the current consumption.

Further, the invention according to claim 5 of the present invention provides:
The non-shared receiving unit has n systems, and a changeover switch for switching the n systems is switched at a clock frequency that is n times the sampling frequency of the I and Q signals of the baseband unit, and the signal separation processing unit of the baseband unit is A / D converter for sampling the demodulated signal at a frequency n times the sampling frequency of the I and Q signals, and a clock having the same frequency as the sampling frequency of the I and Q signals for sequentially storing the demodulated signals of n branches 4. The combination diversity receiver according to claim 2, wherein the storage section discharges the contents of the storage section all at once in synchronization with the combination diversity section, and the number of branches n increases. This can be realized simply by expanding the storage area of the storage unit, so it is easy to realize on a circuit scale, and the scale of the receiving circuit is greatly reduced. Has the effect that it is possible to miniaturize the apparatus.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG.

FIG. 1 shows a first embodiment of the present invention.
3 shows a configuration of a combined diversity receiving apparatus according to an embodiment of the present invention. In FIG. 1, the combining diversity receiving apparatus includes a radio unit 29 and a baseband unit 30, and the radio unit 29 further includes an antenna 31 of the first branch 1, an antenna 32 of the second branch 2, Switch 33, RF amplifier 34, RF-BPF 35, mixer 36, IF
-Consists of a BPF 37, an AGC amplifier 38, and a quadrature detector 39. The baseband unit 30 includes LPFs 40 and 41, and an A / D converter.
It is composed of 42 and 43, demultiplexers 44 and 45, a detector 46, a diversity synthesizer 47, and a timing clock generator 48. 49 indicates a demodulated data output terminal.

The operation of the combining diversity receiving apparatus configured as described above will be described with reference to FIGS. Here, for convenience, the description will be made assuming that the sampling frequency (fs) of the baseband I and Q signals is four times the chip rate (fcp).

The received signals (FIGS. 2 (a) and 2 (b)) input to the antenna 31 of the branch 1 and the antenna 32 of the branch 2 are alternately switched by the changeover switch 33 at a frequency of 2fs. Thereby, the reception signals of the branch 1 and the branch 2 are obtained alternately at a period of 1 / (2fs) (FIG. 2).
(d)).

This received signal is an RF amplifier common to both branches.
34, RF-BPF35, mixer 36, IF-BPF37, AGC amplifier 38, quadrature detector 39, demodulated to baseband signal by LPF40, 41, and converted to digital signal by A / D converters 42, 43 with 2fs sampling frequency After being demultiplexed
By passing the signals through 44 and 45, they are separated into I and Q signals of branch 1 and branch 2 (FIGS. 2 (g) and 2 (h)), detected by a detection unit 46, and a diversity combining unit 47 outputs the signal after the detection. Performs diversity combining using the demodulated data output terminal.
Output to 49.

Thus, the radio section can be realized by one system except for the antenna, so that the size and cost of the apparatus can be reduced.

(Second Embodiment) FIG. 3 shows a second embodiment of the present invention.
3 shows a configuration of a combined diversity receiving apparatus according to an embodiment of the present invention. In FIG. 3, the combining diversity receiving apparatus includes a radio unit 50 and a baseband unit 51. The radio unit 50 further includes an antenna 52 of the first branch 1, an RF amplifier 53 of the first branch 1, Antenna 2 of the second branch 2, an RF amplifier 55 of the second branch 2, a branch switch 56, an RF-BPF 57, a mixer 58, and an IF
-A BPF 59, an AGC amplifier 60, and a quadrature detector 61, and the baseband unit 51 includes LPFs 62 and 63, A / D converters 64 and 65, demultiplexers 66 and 67, and a detection unit. 68,
Diversity combining section 69 and timing clock generator 70
It is composed of Reference numeral 71 denotes a demodulated data output terminal.

The configuration of the radio unit 50 differs from the configuration of the combined diversity receiving apparatus of the first embodiment only in that it is configured with separate antennas 52 and 54 and RF amplifiers 53 and 55 for each branch. This is switched by a branch switch 56.

As a result, the isolation between the branches can be increased, and the interference between the branches can be reduced, so that a higher diversity effect can be obtained.
Further, the size of the apparatus can be reduced and the cost can be reduced as compared with the conventional configuration by sharing the receiving circuit. In addition, RF-BPF57,
Similar effects can be obtained by separating the mixer 58 and the like between branches.

(Third Embodiment) FIG. 4 shows a third embodiment of the present invention.
3 shows a configuration of a combined diversity receiving apparatus according to an embodiment of the present invention. In FIG. 4, the combining diversity receiving apparatus includes a radio unit 72 and a baseband unit 73. The radio unit 72 further includes an antenna 74 of the first branch 1, an antenna 75 of the second branch 2, Switch 76, RF amplifier 77, RF-BPF78, mixer 79, IF
A BPF 80, an AGC amplifier 81, and a quadrature detector 82, and the baseband unit 73 includes LPFs 83, 84, A / D converters 85, 86, 87, 88, a detector 89, Diversity synthesis unit
90, and a timing clock generator 91. Reference numeral 92 denotes a demodulated data output terminal.

The operation of the combining diversity receiving apparatus configured as described above will be described with reference to FIGS. Here, for convenience, the description will be made assuming that the sampling frequency (fs) of the baseband I and Q signals is four times the chip rate (fcp).

The reception signals input to the antenna 74 of the branch 1 and the antenna 75 of the branch 2 are alternately switched by the switch 76 at a frequency of 2 fs.
As a result, the reception signals of branch 1 and branch 2 become 1 / (2f
It is obtained alternately in the cycle of s) (FIG. 5 (d)).

This received signal is an RF amplifier common to both branches.
77, RF-BPF 78, mixer 79, IF-BPF 80, AGC amplifier 81, quadrature detector 82, LPF 83, 84 are demodulated into baseband signals and input to A / D converters 85-88. A / D converter 85,
A / D converter 87 performs A / D conversion at a sample point synchronized with the demodulated signal of branch 1 (FIG. 5 (e)), and A / D converters 86 and 88 perform A / D conversion at a sample point synchronized with the demodulated signal of branch 2. Conversion is performed (FIG. 5 (f)).

As a result, the demodulated signal is separated into I and Q signals of branch 1 and branch 2 and detected by a detection unit 89. A diversity combining unit 90 performs diversity combining using the detected signal, and outputs demodulated data. Output to terminal 92.

As described above, in the combining diversity receiving apparatus according to the third embodiment, I and I of the same sampling frequency are used.
In order to obtain the Q signal, the sampling frequency of the A / D converter is required to be half that of the combining diversity receiver according to the second embodiment, so that the current consumption can be reduced. Further, the size of the apparatus can be reduced and the cost can be reduced as compared with the conventional configuration by sharing the receiving circuit. It should be noted that the same effect can be obtained even if the radio section is configured as in the combining diversity receiver of the second embodiment.

(Fourth Embodiment) FIG. 6 shows the configuration of a combining diversity receiving apparatus according to a fourth embodiment of the present invention. In FIG. 6, the combining diversity receiving apparatus includes a radio unit 93 and a baseband unit 94,
Further, the radio unit 93 includes an antenna 95 of the first branch 1,
The antenna 96 of the second branch 2, the antenna 97 of the (n-1) th branch n-1, and the antenna 98 of the nth branch n
, An antenna changeover switch 99, an RF amplifier 100, and R
F-BPF101, mixer 102, IF-BPF103, and AGC amplifier 104
And a quadrature detector 105. The baseband unit 94 includes LPFs 106 and 107, A / D converters 108 and 109, and a storage unit.
110, 111, a detection unit 112, a diversity combining unit 113,
And a timing clock generator 114. 1
Reference numeral 15 denotes a demodulated data output terminal.

The operation of the combining diversity receiving apparatus configured as described above will be described with reference to FIGS. Here, for convenience, the sampling frequency (fs) of the baseband I and Q signals is set to 4 (chip rate) (fcp).
The description will be made on the assumption that the number of branches is n = 4.

The received signals (FIGS. 7 (a), 7 (b), 7 (c), 7 (d)) input to the antennas of the respective branches are sequentially switched by the changeover switch 99 at a frequency of 4fs. As a result, the received signals of the branches 1 to 4 are sequentially obtained at a period of 1 / (4fs) (FIG. 7 (f)).

This received signal is supplied to an RF amplifier common to each branch.
100, RF-BPF101, mixer 102, IF-BPF103, AGC amplifier 10
4.Demodulated into baseband signals by quadrature detectors 105, LPFs 106 and 107, and the obtained demodulated signals are converted into digital signals by A / D converters 108 and 109 having a sampling frequency of 4fs, and then stored in storage units 110 and 111. Is input to

The storage units 110 and 111 sequentially store the demodulated signals of the respective branches and output the demodulated signals of the respective branches stored at the timing of the clock having the frequency fs. As a result, the I and Q signals of the branches 1 to 4 are separated (FIG. 7).
(j), (k), (l), (m)), detected by the detection unit 112, the diversity combining unit 113 performs diversity combining using the detected signal, and outputs the result to the demodulation data output terminal 115. .

[0034]

As is apparent from the above description, according to the present invention, in a combined diversity receiving apparatus having a plurality of branches, a part of the radio section of the receiving apparatus is reduced for the purpose of reducing the size and cost of the apparatus. A radio unit configured in a system and separately configured for each branch is switched at the same or n times the clock frequency as the sampling frequency of the baseband I and Q signals, and the reception signals of the branches arranged in time series are converted to baseband signals. Demodulated to the baseband section, and after detection, perform diversity combining, thereby achieving an excellent effect that a combined diversity receiving apparatus capable of reducing the size and cost of the apparatus can be obtained. is there.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a combining diversity receiving apparatus according to a first embodiment of the present invention;

FIG. 2 is a timing chart for explaining the operation of the combining diversity receiving apparatus according to the first embodiment of the present invention;

FIG. 3 is a block diagram illustrating a configuration of a combining diversity receiving apparatus according to a second embodiment of the present invention;

FIG. 4 is a block diagram illustrating a configuration of a combining diversity receiving apparatus according to a third embodiment of the present invention;

FIG. 5 is a timing chart for explaining the operation of the combining diversity receiver according to the third embodiment of the present invention;

FIG. 6 is a block diagram showing a configuration of a combining diversity receiving apparatus according to a fourth embodiment of the present invention;

FIG. 7 is a timing chart for explaining the operation of the combining diversity receiving apparatus according to the fourth embodiment of the present invention;

FIG. 8 is a block diagram illustrating a configuration of a combining diversity receiving apparatus according to the related art.

[Explanation of symbols]

1, 2, 29, 50, 72, 93 Radio section 3, 30, 51, 73, 94 Baseband section 4, 15, 31, 32, 52, 54, 74, 75, 95, 96, 97, 98 Antenna 5 , 16, 34, 53, 55, 77, 100 RF amplifier 6, 17, 35, 57, 78, 101 RF-BPF 7, 18, 36, 58, 79, 102 mixer 8, 19, 37, 59, 80, 103 IF-BPF 9, 20, 38, 60, 81, 104 AGC amplifier 10, 21, 39, 61, 82, 105 Quadrature detector 11, 12, 22, 23, 40, 41, 62, 63, 83, 84 , 106,107
LPF 13, 14, 24, 25, 42, 43, 64 A / D converter 65, 85, 86, 87, 88, 108, 109 A / D converter 26, 46, 68, 89, 112 Detector 27, 47, 69, 71, 90, 113 Diversity combining unit 28, 49, 92, 115 Demodulated data output terminal 33, 56, 76, 99 Switch 44, 45, 66, 67 Demultiplexer 48, 70, 91, 114 Timing generation Unit 110, 111 storage unit

Claims (5)

[Claims] 1. A combined diversity receiving apparatus having n branches, wherein the combined diversity receiving apparatus includes a non-shared receiving unit that is a radio unit separately configured for each branch, and a baseband I, A switching switch for switching at the same or n times the clock frequency as the sampling frequency of the Q signal; and a common receiving unit for sharing a circuit between the branches, wherein the common receiving unit is used to demodulate the received signal into a baseband signal. A signal separation processing unit configured to separate a received signal of each branch arranged in time series for each branch, a detection unit configured to perform baseband detection, and a baseband unit. A diversity receiver comprising a diversity combiner for diversity combining the demodulated signals of each branch. 2. When the number n of branches is two,
The non-shared receiving unit is constituted only by an antenna, the other radio unit is a shared receiving unit, and the switching unit alternately switches at a clock frequency twice as high as the sampling frequency of the I and Q signals of the baseband unit. 2. The signal separation processing section of the baseband section, comprising an A / D converter for sampling a demodulated signal at twice the sampling frequency of the I and Q signals, and a demultiplexer. Combined diversity receiver. 3. The combined diversity receiving device according to claim 2, wherein said non-shared receiving unit is constituted by an antenna and an RF amplifier. 4. The switching unit is alternately switched at a clock frequency that is twice the sampling frequency of the I and Q signals of the baseband unit, and the signal separation processing unit of the baseband unit converts the demodulated signals to I and Q signals. 4. An A / D converter which performs sampling at the same frequency as the sampling frequency of each of the branches and at a timing synchronized with the reception signal of each branch.
The combining diversity receiver according to any one of the above. 5. The system according to claim 1, wherein the non-shared receiving unit has n systems.
A changeover switch for switching the system is switched at a clock frequency that is n times the sampling frequency of the I and Q signals of the baseband unit, and the signal separation processing unit of the baseband unit switches the demodulated signal to n of the sampling frequencies of the I and Q signals.
A / D converter that samples at double frequency and demodulated signals of n branches are sequentially stored, and the contents of the storage unit are simultaneously discharged in synchronization with a clock having the same frequency as the sampling frequency of the I and Q signals. The combined diversity receiving device according to claim 2, wherein the combining diversity receiving device is configured by a storage unit.